1. Technical Field
The invention relates to taking an image of a subject by focusing the image on an imaging plane via an optical system including a zoom lens and a focusing lens.
2. Description of the Related Art
With advancement of digital technology, imaging devices, such as digital still cameras and digital video cameras, have widely been used in various fields. The imaging device generally has a zoom mechanism and an auto focusing mechanism. The zoom mechanism moves a zoom lens in response to the operator's zoom operation to change the magnification of an image of a subject. The auto focusing mechanism moves a focusing lens to focus on the subject.
The imaging device typically has a mode for close-up photography called “macro mode”. In close-up or macro photography, the auto focusing mechanism may fail to focus on the subject in the standard mode. In such cases, the image of the subject in close-up distance can be kept in focus by photography in the macro mode. Switching between the standard mode and the macro mode is conventionally performed by the operator's operation of a specified switch.
The operator is accordingly required to perform troublesome switching between the standard mode and the macro mode and may take an image out of focus in macro or close-up photography if the switching is not adequately performed.
Consequently, by taking into account the above problem, there is a need to readily and reliably take an image in focus in macro or close-up photography.